Dolomite Lime in the Garden: When and How to Use It

Dolomite lime—a natural mineral containing calcium and magnesium—offers targeted benefits for specific soil conditions. But it's not universally beneficial; understanding your soil's needs prevents wasted effort or plant damage.

Types and Grades

Available as fine powder (fast-acting) or granules (slow-release). Labels may read "dolomite lime" or "garden lime" if derived from limestone. Check the Ca:Mg ratio—pure dolomite is roughly 2:1 calcium to magnesium; limestone-based products vary.

Key Applications

Fix Molybdenum Deficiency in Legumes

Beans, peas, and other legumes require molybdenum for nitrogen fixation. In acidic soils (pH < 6.0), this nutrient becomes unavailable, causing yellowing and stunting. Dolomite raises pH, restoring molybdenum uptake.

Neutralize Acidic Soil

If soil tests reveal pH below your crops' preferred range (most vegetables: 6.0–7.0), dolomite corrects acidity while supplying calcium and magnesium. It also counteracts acidifying fertilizers and acidic irrigation water.

Prevent Blossom-End Rot

Calcium deficiency causes blossom-end rot in tomatoes, peppers, and squash. Dolomite provides slow-release calcium—apply at planting for season-long protection.

Critical: Test Before Applying

Never add dolomite without a soil test. Excess calcium/magnesium disrupts nutrient balance, and alkaline soils (pH > 7.0) worsen with lime. Follow package rates based on test results and target pH.

Dolomite is a precision tool, not a routine amendment. Used correctly, it solves specific deficiencies; used blindly, it creates new problems.